From cc5b30c6ac03273cfd76975ba83744a210f1704d Mon Sep 17 00:00:00 2001
From: regnat <rg@regnat.ovh>
Date: Fri, 23 Apr 2021 10:54:38 +0200
Subject: [PATCH] Make it easy to build everything as content-addressed

Add a config field `contentAddressedByDefault` and an associated
environment variable `NIXPKGS_CA_BY_DEFAULT` to make every nixpkgs
derivation content-addressed by default
---
 pkgs/stdenv/generic/make-derivation.nix | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pkgs/stdenv/generic/make-derivation.nix b/pkgs/stdenv/generic/make-derivation.nix
index 5b446b118269..2bceb9e4333e 100644
--- a/pkgs/stdenv/generic/make-derivation.nix
+++ b/pkgs/stdenv/generic/make-derivation.nix
@@ -89,7 +89,10 @@ in rec {
 
     , patches ? []
 
-    , __contentAddressed ? false
+    , __contentAddressed ?
+      (! attrs ? outputHash) # Fixed-output drvs can't be content addressed too
+      && (config.contentAddressedByDefault or false
+          || builtins.getEnv "NIXPKGS_CA_BY_DEFAULT" == "1")
 
     , ... } @ attrs: